KR20010051796A - Granular organosilane preparation, process for the production thereof and use thereof - Google Patents

Abstract

PURPOSE: Provided are organosilane preparation in granulated form, and its manufacture process and use. CONSTITUTION: Organosilane granulate, consisting of organosilane(s) and filler(s), contains less than 2% very fine fraction. The organosilane granulate is represented by the formula(1), wherein R1 is monovalent alkyl having 1-3 carbons; R2 is monovalent alkyl having 1-3 carbons or alkoxy; R is bivalent alkyl having 1-5 carbons; and X is a value of 2.0-6.0.

Description

Granular organosilane preparation, process for the production approximately and use

FIELD OF THE INVENTION The present invention relates to organosilane preparations, methods for their preparation and uses.

Organosilicon compounds are used in rubber technology. In particular, it is known to be used in sulfur-containing alkoxysilanes to make good coupling and reinforcing agents for the vulcanization of rubber compounds containing silicate fillers. These in particular include organosilanes according to US Pat. No. 3,422,111.

Reinforcing additives for rubber vulcanization made from liquid organosilanes and silicate fillers of US Pat. No. 3,42,111 (German Patent No. 2255577 and US Pat. No. 3997356) are also known.

All organosilanes established in the art so far for the stated purpose are condensed with alcohol decomposition when contacted with water, which is a gas or liquid, to produce high molecular weight polysiloxanes, whereby hydrolysis which at least somewhat loses its efficacy as a reinforcing additive. Possible liquid.

In the rubber processing industry, auxiliary chemicals that are liquid at room temperature, and thus organosilanes that are liquid, present a serious disadvantage compared to solid powder auxiliary chemicals. They require a lot of effort in storage, weighing and weighing in silos. First of all, they show poor mixing when preparing compounds in roll compounders.

To compensate for this drawback, the liquid organosilane is mixed with the powder filler to obtain a powder product. In spite of this help, the optimum solution cannot be formed because it is relatively difficult to include the powdered product in the rubber compound. Thus, extended mixing time is required. Powders pollute the environment and machinery. It was also noted that the sensitivity to hydrolysis seen by silane is not eliminated. In addition, if products are stored, they become significantly less effective. This is expressed, for example, in the reduction of the final crosslinking level with respect to rubber vulcanization.

Also known are mixtures of organosilanes and fillers of the formula (1), which are present as granular preparations and comprise 30 to 60% by weight of at least one organosilane and 70 to 40% by weight of at least one carbon black (German Patent No. 2747277). ).

In Formula 1 above,

R ¹ means a monovalent alkyl residue having 1 to 3 carbon atoms,

R ² means monovalent alkyl or alkoxy moiety having 1 to 3 carbon atoms,

R means a divalent alkyl moiety having 1 to 5 carbon atoms,

x is a value from 2.0 to 6.0.

These mixtures have the disadvantage of having a relatively high particulate content and a high content of pellet parts of less than 0.125 mm.

It is an object of the present invention to provide organosilane preparations which do not exhibit this disadvantage.

1 is a schematic diagram of a mixing granulator.

2A shows an organosilane preparation according to Example 1 of German Patent No. 2747277, and FIG. 2B shows an organosilane preparation according to Example 4 of the present invention.

3A shows the mass flow established in the bulk material vessel upon product discharge and FIG. 3B shows the bulk material bridge formed in the bulk material vessel upon mass flow.

FIG. 3C shows the funnel flow established in the bulk material container upon product discharge, and FIG. 3D shows the formation of a rat hole in the bulk material container upon funnel flow.

The present invention provides granular organosilane preparations comprising a mixture of one or more organosilanes and one or more fillers, characterized in that they comprise less than 2%, preferably less than 0.5%, of particulate components.

The organosilane preparation may comprise less than 2%, preferably less than 0.5%, of pellet components less than 0.125 mm.

The silane content of the organosilane preparation according to the invention amounts to 1 to 70% by weight, preferably 40 to 55% by weight, relative to the organosilane preparation. The organosilane may comprise any known organosilane, but is preferably a Degussa-Wheels Actiengegelshaft product of Si 69, Si 264, Si 230, Si 116, Si 216, Si 203, Si 108, Si 118, Si 208, Si 255, Si 270, Si 275, Si 75, Dynasilan MTMO or Dynasilane MEMO.

The filler content amounts to 30 to 99% by weight, preferably 45 to 60% by weight relative to the organosilane preparation according to the invention. Fillers may comprise rubber black or pigment black, preferably "Information fur die Gummiindustrie", Degussa AG, PT 39-4-05-1287 Ha and "Pigment Blacks", Degussa AG PT 80-0-11- Corrax N 121, Corrax N 110, Corrax N 242, Corrax N 234, Corrax N 220, Corrax N 375, Corrax N 356, Corrax N 347, Corrax from Degussa-Wheels Actigen Gel Shafts described in 10 86 Ha N 339, Corrax N 332, Corrax N 330, Corrax N 326, Corrax N 550, Corrax N 539, Corrax N 683, Corrax N 660, Corrax N 774, Corrax N 765, Corrax N 650, Corrax N 762, Durex ( Durex) 0, Corrax 3, Corrax 4, Corrax 9, Corrax P, Printex P, Corrax S 315, CK 3, Corrax XE-1, Printex L, Printex L 6, Corex L 29, Printex XE 2, Farbruß FW 200, Farburs FW 2, Farburs FW 2 V, Farburs FW 1, Farburs FW 18, Spezialus 6, Farbu Ruth S 170, Parbour S S 160, Spezialus 5, Spezialus 4, Spezialus 4 A, Printex 150 T, Printex U, Printtex V, Printtex 140 U, Printtex 140 V, Printtex 95, Printtex 90, Printtex 85, Printtex 80, Printtex 75, Spezialus 550, Printtex 55, Printtex 45, Printtex 40, Printtex 60, Printtex XE 2, Printtex L 6, Print Tex L, Printex 300, Printex 30, Printex 3, Spezalus 350, Printex 35, Spezalus 250, Printex 25, Printex 200, Printex A, Spezialus 100, Printex G, Flammruß 101.

Particular preference is given to using carbon blacks having a DBP value of greater than 100 ml / 100 g. Carbon black can be used in wet-pelletized form or in dry-pelletized form or in powder form.

In addition, silica can be used as the filler, with the Degussa-Wheels Actigengelshaft Ultrasil VN3, Ultrasil VN2, Ultrasil 3370 or Ultrasil 7000 being preferred.

The present invention also provides a method for producing a granular organosilane preparation, which method is characterized by mixing at least one organosilane with a filler and using a mixing granulator as the mixing device. The filler may be dispensed into the mixing granulator by gravimetric powder metering. The mixed material may be carried to the outlet by a spike shaft (FIG. 1). The silane may be dispensed in volume or weight. The silane may be injected into one or more nozzles at one or more points. Mixing temperature is 40-140 degreeC, Preferably it is 60-120 degreeC. The speed may vary in the range of 100 to 1500 rpm, preferably 100 to 1000 rpm. Filler throughput can vary between 10 and 150 kg / h, preferably between 20 and 80 kg / h. Power consumption amounts to 10 to 30 A. Filler throughput for one production facility may vary between 0.5 and 1.5 t / h. The circumferential speed of the spike tip can reach 1 to 30 m / s, preferably 10 to 20 m / s. The residence time of the filler in the mixing granulator can range from 20 to 600 seconds.

In addition to the method of injecting the organosilane, the injection point also has a significant effect on the quality of the formed preparation.

The mixing granulator consists of a stationary tube (stator) with a rotating spike shaft placed horizontally. The mixed granulator typically comprises an inlet portion from which the starting filler is fed to the mixed granulator. At this point, a conveying screw is placed which imparts an axial motion component to the supplied filler. Next to the inlet portion is an appropriate granulation section, in which the filler agglomerates through the mechanical movement of the rotating spike and by rotating against the inner wall of the stator. After leaving the granulation section, the pelletized filler reaches the outlet section and is continuously discharged from the mixing granulator.

According to the design of the mixing granulator, each part of the mixing granulator has a different size. In either case, the inlet and outlet portions should be kept as small as possible in favor of the granulation portions. Once the powder starting filler enters the granulation section, the agglomeration of the filler starts and at the end of this section the agglomeration is complete. In order to ensure that the organosilane is distributed as uniformly as possible over the entire cross-sectional area of the filler pellets, it is necessary to spray the organosilane to the filler within the first third of the granulation section. Introducing organosilanes at a later stage of pellet formation results in a non-uniform filler pellet structure which reduces pellet hardness.

To include the organosilane more uniformly in the filler, a plurality of spray nozzles can be used for spraying, which are distributed around the stator in a plane perpendicular to the spike shaft.

The number of nozzles can be suitably limited to 2-5. The nozzles are arranged in a plane perpendicular to the spike shaft, ensuring good introduction uniformity.

The small distance between the spike tip of the stator and the inner wall prevents sedimentation to the maximum extent possible. In this way, the silane can be more evenly distributed in the filler.

The granular organosilane preparations according to the present invention appear to have an advantage in pneumatic conveying, silo storage and introduction into rubber, which are superior to known organosilane preparations.

The organosilane preparations according to the invention are explained in more detail with reference to the drawings, where FIG. 1 is a schematic diagram of a mixing granulator.

According to FIG. 1, the mixing granulator consists of a stationary tube lying horizontally, ie the stator 1, and a rotating spike shaft 2 arranged axially of the stator with a spiral 3 placed in a helical manner. Between the spike shaft 2 and the stator 1, a mixing granulator pelleting chamber is located. Filler is supplied to the granulator at the inlet (5). In the inlet region, a transport screw 6, which transports the filler axially to the outlet 7, is located above the spike shaft 2. The stator 1 is of double wall construction and allows liquid 8 to control the temperature of the stator wall. Within the first third of the granulation part of the stator, there is a through hole at the top, through which a spray nozzle 9 for introducing the organosilane is introduced.

Granular organosilane preparations are used in vulcanizable rubber compounds.

Example

Carbon black N 330 powder is used as filler. Its physicochemical properties are listed in Table 1.

Bulk Density [g / l] DBP [ml / 100g] CTAB [m ² / g] Iodine Value [mg / g] moisture[%] N 330 77 122 86 93 0.5

Various test conditions for the mixed granulators used are listed in Table 2.

As a comparative example, an organosilane preparation according to Example 1 of German Patent No. 2747277 is prepared as follows:

Weigh 10 kg of N 330 and 10 kg of bis- (3-triethoxysilylpropyl) tetrasulfide (abbreviated as Si 69) into a trough-shaped powder mixer with a propeller-type mixing device and a capacity of 150 liters, The two are homogenized by complete treatment at 360 rpm for 25 seconds. The apparatus used is described in DE-OS 15 92 861.

Example One 2 3 4 5 N 330 kg / h 25 25 26.5 26.5 33 Si 69 kg / h 26.4 26.4 26.5 26.5 36 Silane content wt.% 51.4 51.4 50.0 50.0 52.2 Nozzle position 5 cm bottom of carbon black powder inlet Nozzle mm 1.3 1.3 1.3 1.3 1.3 Nozzle pressure bar 4 1.5 1.5 0.8 1.5 Mixer speed rpm 650 650 714 650 550 Mixer power consumption A 15.5-16.5 16.5-17.5 16-17.5 15.5-17 15.5-18 Mixer temperature ℃ 100 100 100 100 100 Final product temperature ℃ About 60 About 60 About 60 About 60

The characteristic data of the organosilane preparations obtained are listed in Tables 3 and 4.

Example Appearance evaluation Example 1 Various pelletized colors with slight agglomeration: dark gray Very good flow behavior Example 2 Same as Example 1 Example 3 Uniform pelletized color with slight agglomeration: dark gray Very good flow behavior Example 4 Uniform micropellet pellet with slight coagulation Color: dark gray Very good flow behavior Example 5 Very coarse material color with some agglomeration: dark gray Very good flow behavior

The organosilane preparations according to the invention have a significantly lower particulate content and a lower pellet content of less than 0.125 mm compared with the comparative examples according to German Patent No. 2747277. Thus, the blockade of the line during air transport need not be predicted.

Comparison of micrographs (8x magnification) according to FIG. 2 shows a marked improvement in pellet quality and lower particulate content. 2A shows an organosilane preparation according to Example 1 of German Patent No. 2747277, and FIG. 2B shows an organosilane preparation according to Example 4 of the present invention.

While the known organosilane preparations are agglomerated, the organosilane preparations according to the invention show a clear advantage when visually observed.

Analyze in any way:

Bulk Density ASTM D1513

DBP ASTM D2414

CTAB ASTM D3765

Iodine Value ASTM D1510

Moisture ASTM D1509

Particulate Content ASTM D1508

Volatile Part ASTM D1509

Sulfur Content DIN 51400

The pellet size distribution is measured as follows:

Sieve (standard US sieve, 25 mm high, 200 mm diameter, 0.125 mm, 0.25 mm, 0.50 mm, 0.71 mm, 1.0 mm, 1.5 mm mesh size) and collector pans in a predetermined arrangement, i.e. the mesh size is reduced from top to bottom. Install together. 100 g of the carbon black to be tested are weighed using a suitable spoon. Under no circumstances should carbon black be poured from the barrel, because pellet preselection occurs. A weighing carbon black is transferred to the top sieve, the lid is in place and the stack is about 1.5 mm gap so that the sieve can rotate freely (sieving machine, Ro-tap No. 704). To be introduced. The cover plate should have a cork. The sieve is fixed to the machine and then shaken for 1 minute with a working hammer. The sieves are then separated in succession and the amount of carbon black present in each is weighed to an accuracy of 0.1 g.

Evaluation of Silo Storage Behavior

In order to ensure trouble free operation of the silo, the geometry of the discharge hopper must be known. This can be determined by measuring the fluidity of the bulk material and its consolidation behavior during silo storage using a Jenike shear apparatus. Process-engineering silo dimensioning is either the axially symmetrical (round bottom) or vertical (rectangular bottom) slope of the hopper wall of the silo and the minimum diameter (Dmin) or minimum width (Bmin) of the hopper wall. ), And if these variables are fixed, trouble-free operation of the silo is ensured. If the hopper tilt angle is specified or small, then mass flow (FIG. 3A) is established in the form of flow in the bulk material container as the product is released, ie the entire container contents move uniformly. On this basis, material release can only be hampered by the formation of a stable bulk material bridge (FIG. 3B). If the diameter of the discharge opening is large enough, it is impossible to form a stable bulk material bridge upon product release. If the bulk material aggregates during storage, the minimum diameter of the discharge opening increases with bulk material aggregation to prevent bridge formation. If mass flow cannot be achieved as the flow profile, funnel flow (FIG. 3C) is established as the flow form. If the funnel flow prevails in the bulk material container, the formation of a stable rathole (FIG. 3D) will make it impossible for the silo to fully empty. The slope of the hopper wall is then dimensioned from the point of view of preventing the formation of a stable rat hole without any influence on the release behavior of the bulk material.

Jenike's flowability index is commonly used to describe fluidity in general. Bulk material stability (fc) alone is insufficient to assess the fluidity of the bulk material because the fluidity depends on the cohesive stress (σ1). Therefore, Niknik introduced ffc, a relationship between cohesive stress and bulk material stability as a measure of the flow of bulk material.

The lower the ffc value, the less flow the bulk material. According to Jenique, the following classification applies:

ffc〉 10 free flowing

ffc 10-4 approximate flow

ffc 4-2 cohesive

ffc <2 very cohesive, not flowing

Since the ffc value depends on the cohesive stress, it is reasonable to always apply the same stress level when comparing the flowability of bulk materials.

Variables and fluidity indices (ffc) required for process-engineering silo dimensioning can be measured by shear tests using the Zenique shear device (Messung des Scherweg- / Scherkraftverlaufes bei verschiedenen Normalspannungen und der Bestimmung der Reibungsverhaltnisse zwischen Behalterwandmaterial) Measurement of the shear path / shear force profile at various normal stresses and determination of the frictional relationships between container wall material and bulk material, (Peter Mertens: Silohandbuch, Ernst + Sohn Verlag, Berlin 1988, pp. 50-52).

This type of shear test allows comparing the flow and storage behavior of the product according to the invention with the comparative example according to German Patent No. 2747277, and the process-engineering silo dimensions of silos with an estimated wall inclination of 25 ° relative to the vertical line. Allow anger.

Instantaneous Flow Behavior of Comparative Example According to German Patent No. 2747277 Shear stress 2580 Pa Shear stress Shear stress σ1 [Pa] fc [Pa] ffc σ1 [Pa] fc [Pa] ffc σ1 [Pa] fc [Pa] ffc Comparative Example German Patent No. 2747277 5310 1380 3.8 7879 1984 4.0 14270 2853 5.0

In a comparative example according to German Patent No. 2747277, bulk material stability as a function of storage time Shear stress: 3850 Pa Bulk Material Stability fc [Pa] Hour [day] 0 One 3 5 Comparative Example According to German Patent No. 2747277 1984 2220 3300 7730

Comparative Example In German Patent No. 2747277, the minimum diameter of the discharge opening when the hopper wall slope θax = 25 ° of the silo assumed to be axially symmetrical Diameter of discharge opening Dmin [mm] Hour [day] 0 One 3 5 Comparative Example According to German Patent No. 2747277 335 380 875 2640

Instantaneous Flow Behavior of Example 5 Shear stress2 120 Pa Shear stress3560 Pa Shear stress64 60 Pa σ1 [Pa] fc [Pa] ffc σ1 [Pa] fc [Pa] ffc σ1 [Pa] fc [Pa] ffc Example 5 5360 470 11 8880 820 11 16010 2095 7.6

Bulk material stability as a function of storage time for Example 5 Shear stress: 3560 Pa Bulk Material Stability fc [Pa] Hour [day] 0 One 7 14 Example 5 470 640 640 640

For Example 5, the minimum diameter of the discharge opening when the hopper wall slope θax = 25 ° of the silo assumed to be axially symmetrical Diameter of discharge opening Dmin [mm] Hour [day] 0 One 7 14 Example 5 〈30 30 30 30

The comparison of the minimum diameter, bulk material stability and flow index to prevent bridge formation indicates that the products produced by the process according to the invention are remarkably good in fluidity and silo storage (Tables 5 to 10). After two weeks of storage, the product flows out of the silo without difficulty. When the comparative example according to German patent 2747277 is stored in a silo, the problem of release occurs even after only three days of storage.

Transport behavior evaluation

Transport and polishing behavior in pneumatic conveying installations is assessed using transport tests in lean and thick phase transport installations. Finally, the transported material is repeatedly transported in the transport facility described below with the indicated device. Abrasive behavior is compared using the particle size distribution of the material supplied and transported, and calculating the balance of the resulting particulates.

Dilute phase transport facility

The lean phase transport facility consists of a supply vessel with a blow-through lock for material supply, a collection vessel arranged there, a pressure supply nitrogen supply connection, two cyclone for material separation and two downstream filters. Is done. The transport line is 44m long, of which 6.3m takes the form of a rising line and has seven 90 ° bends. The inner line diameter is 56.3 mm. The plant is operated with nitrogen. To achieve better particulate separation, only one of the two cyclones is used.

Dense phase transport facility

The concentrate transport facility consists essentially of a pressure transfer vessel, a hose type transfer line (D _internal = 60 mm) and a separation vessel, a dust filter connected downstream. The transport length is 39 m, whose 5.7 m extends in the form of a vertical rise line. The line includes four 90 ° bends and one 180 ° bend. Transport gas (nitrogen) is introduced in two substreams (upper air and lower air) via Laval nozzles.

Tables 11-13 list the transport conditions / apparatuses.

Lean Transport in Example 5 Test 1 Test 2 Gas mass flow rate [kg / h] 200 300 Volumetric flow rate [m ³ / h] 166.7 250.0 Pressure loss [mbar] 225 315 Initial weight [kg] 49.6 50.8 Time [mins] 3.58 2.5 Mass flow rate [kg / h] 831 1219 Loading μ [kg solid / kg transport gas] 4.2 4.1 v, transport gas [m / s] 18.8 28.2 Gas density [kg / m ³ ] 1.2 1.2 Gas temperature [℃] 20 20 Total transport distance [m] 132 132

Tables 14-17 list the pass-through values D 90%, D 50% and D 10% for the cumulative passage distribution of the transported material and the starting material.

Test 1, lean transport Pass Starting material Transport distance: 42m Transport distance: 132m D 10% 890 990 900 D 50% 1270 1480 1670 D 90% 1760 2200 2060

Test 2, lean transport Pass Starting material Transport distance: 42m Transport distance: 132m D 10% 810 - 720 D 50% 1210 - 1120 D 90% 1775 - 1670

Test 1, concentrated phase transport Pass Starting material Transport distance: 39m Transport distance: 195m D 10% 790 1080 850 D 50% 1190 1510 1245 D 90% 1975 2095 1810

Test 2, concentrated phase transport Pass Starting material Transport distance: 39m Transport distance: 195m D 10% 840 700 650 D 50% 1240 1110 1090 D 90% 1810 1610 1590

The product according to the invention can be reliably transported without difficulty to the lean and concentrated phases within the stated limits. The lean and concentrated phase transports with a transport gas velocity of 28 m / s or less do not significantly increase the particulate content. After the lean transport exceeds the distance of 132 m or the concentrated transport exceeds the distance of 195 m, the material is present in the form of dust-free granules. After air transport, the transported material shows no change in its good bulk material properties.

The present invention provides granular organosilane preparations having a very low particulate content and a low pellet fraction content of less than 0.125 mm, which are excellent in air transport, silo storage and introduction into rubber.

Claims (11)

A granular organosilane formulation comprising a mixture of one or more organosilanes and one or more fillers, wherein the granular organosilane formulation comprises less than 2% of particulate components. The organosilane preparation of claim 1 comprising less than 2% of a pellet component of less than 0.125 mm. The organosilane preparation according to claim 1 or 2, wherein the silane content is 1 to 70% by weight relative to the granular organosilane preparation. The organosilane preparation according to any one of claims 1 to 3, wherein carbon black or silica is used as a filler. At least one organosilane is mixed with a filler and a heatable mixed granulator is used as the mixing device. The method of claim 5 wherein the filler is dispensed by gravimetric powder metering. 6. A process for the preparation of an organosilane preparation according to claim 5, wherein the silane is distributed by volume or by weight. The method of claim 5 wherein the silane is injected by one or more nozzles at one or more points. 6. A process according to claim 5, wherein the mixing is carried out at a mixing temperature of 40 to 140 &lt; 0 &gt; C. The method for producing an organosilane preparation according to claim 5, wherein the speed of the mixing granulator varies in the range of 100 to 1500 rpm. Use of the granular organosilane preparation according to claim 1 in vulcanizable rubber compounds.